Zahra Mokhtari - Department of Animal Science, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran
Ahmad Ahmadi - Department of Animal Sciences, Faculty of Agriculture, Bu-Ali Sina University, Hamedan - IRAN
Pouya Zamani - Department of Animal Science, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran
Reza Talebi - Department of Systems and Synthetic Biology, Agricultural Biotechnology Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
Mohammad Reza Ghafari - Department of Systems and Synthetic Biology, Agricultural Biotechnology Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran

Follicle-stimulating hormone (FSH) is necessary for the hypothalamic-pituitary-gonadal axis, and plays an important role in reproduction by binding to a specific receptor (FSHR) through β-subunit of FSH in the surface of the ovarian granulosa cells. This study aimed to characterize FSH β-subunit gene (FSHβ) polymorphism and its association with litter size (LS) using a sample of ۱۱۸ Mehraban sheep. Polymerase chain reaction (PCR) was performed to amplify two fragments of ۳۰۰ bp and ۴۳۱ bp of the ovine FSHβ gene (Oar_v۴.۰; Chr ۱۵, NC_۰۱۹۴۷۲.۲). Polymorphisms in the studied fragments were then explored using single strand conformational polymorphism (SSCP) and DNA sequencing methods. A total of seven single-nucleotide polymorphisms (SNPs), including g.۵۹۰۷۸۵۶۴ C>G, g.۵۹۰۷۸۶۲۴ T>C, g.۵۹۰۷۸۶۵۵ T>C, g.۵۹۰۷۸۶۹۱ T>C, g.۵۹۰۷۸۷۵۴ C>A, g.۵۹۰۸۰۱۸۶ G>C and g.۵۹۰۸۰۳۶۵ C>T, were found among the six detected SSCP patterns A to F. Moreover, two novel indel polymorphisms called e.g., g.۵۹۰۷۸۷۰۲del۸-bp−ins۶۴-bp and g.۵۹۰۷۸۷۲۶ins۵۴-bp were identified among the three different SSCP genotypes patterns G to I. We found significant differences on prolificacy categories between SSCP genotypes patterns D, E and F (P < ۰.۰۱) that simultaneously represented SNP polymorphisms of g.۵۹۰۷۸۷۵۴ C>A, g.۵۹۰۸۰۱۸۶ G>C and g.۵۹۰۸۰۳۶۵ C>T. Similarly, novel indel polymorphisms revealed a significant difference on prolificacy categories between SSCP genotypes patterns G, H and I (P < ۰.۰۵). Our results suggest that the FSHβ is a strong candidate gene to associate with the LS in sheep.

FSHβ gene, litter size, Mehraban sheep, polymorphism